PARTIAL DISCHARGE DETECTOR FOR ELECTRIC APPARATUS

PURPOSE:To always surely and highly accurately detect the generating position of partial discharge by finding out an error between the theoretical value of a delay time obtained in the case of assuming that an optional point in a tank is a partial discharge generating position and a delay time detected by an acoustic pulse detector. CONSTITUTION:When partial discharge is generated in the tank 1, and electric pulse and an acoustic pulse generated due to the generation of the partial discharge are respectively detected by an electric pulse detector 5 and acoustic pulse detectors 4a to 4c. A delay time detector 5 detects the delay time of the acoustic pulse from a time difference between the detected electric pulse and the detected acoustic pulse and inputs the detected delay time to an arithmetic unit 6A. The arithmetic unit 6A calculates the logical value of the delay time by assuming an optional point in the tank 1 as a partial discharge generating position, finds out an error between the delay time logical value and the delay time of the acoustic pulse and regards the position with a minimum error as the partial discharge generating position.